Enhanced Topical Delivery of Drugs to the Eye Using Chitosan Based Systems

Abstract

Topical administration is considered to be the favored route for ocular drug delivery by virtue of drug penetration into the underlying layers of eye. Targeted delivery of drugs to the ocular tissues especially at the posterior segment of eye is hindered predominantly. Long-term maintenance of therapeutic level of drugs in the ocular tissue (both anterior/posterior segments) is the major specific challenge faced by researchers. Development of novel pharmaceutical formulations may overcome these barriers and imparts therapeutic levels in eye. In this regimen chitosan due to its avoidance of toxicity, biocompatibility, bioadhesion, and permeability-enhancing properties is widely used in ocular topical drug delivery. Chitosan facilitates the transport of drugs to the inner eye or accumulation into the corneal/conjunctival epithelia due to its mucoadhesion and permeation-enhancing properties. In this chapter will be provided insights toward the different ocular barriers, conventional and novel chitosan based ocular topical drug delivery systems. Special emphasis will be made toward the development of chitosan based topical delivery systems for ocular diseases.